// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.apache.tapestry.contrib.form;
import java.io.IOException;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.HiveMind;
import org.apache.tapestry.IActionListener;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.form.AbstractFormComponent;
import org.apache.tapestry.listener.ListenerInvoker;
import org.apache.tapestry.services.DataSqueezer;
/**
* A conditional element on a page which will render its wrapped elements zero or one times. This
* component is a variant of {@link org.apache.tapestry.components.Conditional}, but is designed
* for operation in a form. The component parameters are stored in hidden fields during rendering
* and are taken from those fields during the rewind, thus no StaleLink exceptions occur. [ <a
* href="../../../../../ComponentReference/contrib.FormConditional.html">Component Reference </a>]
*
* @author Mindbridge
* @since 3.0
*/
public abstract class FormConditional extends AbstractFormComponent
{
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
IForm form = getForm(cycle);
boolean cycleRewinding = cycle.isRewinding();
// If the cycle is rewinding, but not this particular form,
// then do nothing (don't even render the body).
if (cycleRewinding && !form.isRewinding())
return;
String name = form.getElementId(this);
boolean condition = getCondition(cycle, form, name);
getListenerInvoker().invokeListener(getListener(), this, cycle);
// render the component body only if the condition is true
if (condition)
{
String element = getElement();
boolean render = !cycleRewinding && HiveMind.isNonBlank(element);
if (render)
{
writer.begin(element);
renderInformalParameters(writer, cycle);
}
renderBody(writer, cycle);
if (render)
writer.end(element);
}
}
private boolean getCondition(IRequestCycle cycle, IForm form, String name)
{
boolean condition;
if (!cycle.isRewinding())
{
condition = getCondition();
writeValue(form, name, condition);
}
else
{
String submittedCondition = cycle.getParameter(name);
condition = convertValue(submittedCondition);
}
if (isParameterBound("conditionValue"))
setConditionValue(condition);
return condition;
}
private void writeValue(IForm form, String name, boolean value)
{
String externalValue;
try
{
externalValue = getDataSqueezer().squeeze(value ? Boolean.TRUE : Boolean.FALSE);
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(Tapestry.format(
"FormConditional.unable-to-convert-value",
Boolean.toString(value)), this, null, ex);
}
form.addHiddenValue(name, externalValue);
}
private boolean convertValue(String value)
{
try
{
Boolean b = (Boolean) getDataSqueezer().unsqueeze(value);
return b.booleanValue();
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(Tapestry.format(
"FormConditional.unable-to-convert-string",
value), this, null, ex);
}
}
public abstract DataSqueezer getDataSqueezer();
// Part of the FormElement interface.
public boolean isDisabled()
{
return false;
}
public abstract boolean getCondition();
public abstract void setConditionValue(boolean value);
public abstract String getElement();
public abstract IActionListener getListener();
/**
* Injected.
*
* @since 4.0
*/
public abstract ListenerInvoker getListenerInvoker();
}